1 files changed, 100 insertions, 0 deletions
diff --git a/toolkit/components/backgroundtasks/tests/xpcshell/test_backgroundtask_simultaneous_instances.js b/toolkit/components/backgroundtasks/tests/xpcshell/test_backgroundtask_simultaneous_instances.js
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+++ b/toolkit/components/backgroundtasks/tests/xpcshell/test_backgroundtask_simultaneous_instances.js
@@ -0,0 +1,100 @@
+/* -*- indent-tabs-mode: nil; js-indent-level: 2 -*-
+ * vim: sw=4 ts=4 sts=4 et
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+// Display logging for ease of debugging.
+let moz_log = "BackgroundTasks:5";
+
+// Background task temporary profiles are created in the OS temporary directory.
+// On Windows, we can put the temporary directory in a testing-specific location
+// by setting TMP, per
+// https://docs.microsoft.com/en-us/windows/win32/api/fileapi/nf-fileapi-gettemppathw.
+// On Linux, this works as well: see
+// [GetSpecialSystemDirectory](https://searchfox.org/mozilla-central/source/xpcom/io/SpecialSystemDirectory.cpp).
+// On macOS, we can't set the temporary directory in this manner, so we will
+// leak some temporary directories.  It's important to test this functionality
+// on macOS so we accept this.
+let tmp = do_get_profile();
+tmp.append("Temp");
+
+add_setup(() => {
+  if (Services.env.exists("MOZ_LOG")) {
+    moz_log += `,${Services.env.get("MOZ_LOG")}`;
+  }
+
+  tmp.createUnique(Ci.nsIFile.DIRECTORY_TYPE, 0o700);
+});
+
+async function launch_one(index) {
+  let sentinel = Services.uuid.generateUUID().toString();
+  sentinel = sentinel.substring(1, sentinel.length - 1);
+
+  let stdoutLines = [];
+  let exitCode = await do_backgroundtask("unique_profile", {
+    extraArgs: [sentinel],
+    extraEnv: {
+      MOZ_BACKGROUNDTASKS_NO_REMOVE_PROFILE: "1",
+      MOZ_LOG: moz_log,
+      TMP: tmp.path, // Ignored on macOS.
+    },
+    onStdoutLine: line => stdoutLines.push(line),
+  });
+
+  let profile;
+  for (let line of stdoutLines) {
+    if (line.includes(sentinel)) {
+      let info = JSON.parse(line.split(sentinel)[1]);
+      profile = info[1];
+    }
+  }
+
+  return { index, sentinel, exitCode, profile };
+}
+
+add_task(async function test_backgroundtask_simultaneous_instances() {
+  let expectedCount = 10;
+  let promises = [];
+
+  for (let i = 0; i < expectedCount; i++) {
+    promises.push(launch_one(i));
+  }
+
+  let results = await Promise.all(promises);
+
+  registerCleanupFunction(() => {
+    for (let result of results) {
+      if (!result.profile) {
+        return;
+      }
+
+      let dir = Cc["@mozilla.org/file/local;1"].createInstance(Ci.nsIFile);
+      dir.initWithPath(result.profile);
+      try {
+        dir.remove();
+      } catch (e) {
+        console.warn("Could not clean up profile directory", e);
+      }
+    }
+  });
+
+  for (let result of results) {
+    Assert.equal(
+      0,
+      result.exitCode,
+      `Invocation ${result.index} with sentinel ${result.sentinel} exited with code 0`
+    );
+    Assert.ok(
+      result.profile,
+      `Invocation ${result.index} with sentinel ${result.sentinel} yielded a temporary profile directory`
+    );
+  }
+
+  let profiles = new Set(results.map(it => it.profile));
+  Assert.equal(
+    expectedCount,
+    profiles.size,
+    `Invocations used ${expectedCount} different temporary profile directories`
+  );
+});